fix: use random table for read_pandas (#192)

* fix: use random table for read_pandas * fix: default to 7 days expiration for `read_csv`, `read_json`, `read_parquet` (#193) Thank you for opening a Pull Request! Before submitting your PR, there are a few things you can do to make sure it goes smoothly: - [ ] Make sure to open an issue as a [bug/issue](https://togithub.com/googleapis/python-bigquery-dataframes/issues/new/choose) before writing your code! That way we can discuss the change, evaluate designs, and agree on the general idea - [ ] Ensure the tests and linter pass - [ ] Code coverage does not decrease (if any source code was changed) - [ ] Appropriate docs were updated (if necessary) Follow-up to https://togithub.com/googleapis/python-bigquery-dataframes/pull/175/files#r1389686556 🦕 * fix: use random table for read_pandas * fix: use the real table expression --------- Co-authored-by: Tim Swast <swast@google.com>

Author: ashleyxuu

bigframes/core/__init__.py

@@ -165,7 +165,7 @@ def cached(self, cluster_cols: typing.Sequence[str]) -> ArrayValue:
  ibis_expr = compiled_value._to_ibis_expr(
  ordering_mode="unordered", expose_hidden_cols=True
  )
- tmp_table = self.session._ibis_to_session_table(
+ tmp_table = self.session._ibis_to_temp_table(
  ibis_expr, cluster_cols=cluster_cols, api_name="cached"
  )
 

bigframes/session/__init__.py

@@ -36,7 +36,6 @@
  Tuple,
  Union,
 )
-import uuid
 import warnings
 
 import google.api_core.client_info
@@ -986,7 +985,7 @@ def _read_pandas(
  job_config.clustering_fields = cluster_cols
  job_config.labels = {"bigframes-api": api_name}
 
- load_table_destination = self._create_session_table()
+ load_table_destination = bigframes_io.random_table(self._anonymous_dataset)
  load_job = self.bqclient.load_table_from_dataframe(
  pandas_dataframe_copy,
  load_table_destination,
@@ -999,8 +998,9 @@ def _read_pandas(
  total_ordering_columns=frozenset([ordering_col]),
  integer_encoding=IntegerEncoding(True, is_sequential=True),
  )
- table_expression = self.ibis_client.sql(
- f"SELECT * FROM `{load_table_destination.table_id}`"
+ table_expression = self.ibis_client.table(
+ load_table_destination.table_id,
+ database=f"{load_table_destination.project}.{load_table_destination.dataset_id}",
  )
 
  # b/297590178 Potentially a bug in bqclient.load_table_from_dataframe(), that only when the DF is empty, the index columns disappear in table_expression.
@@ -1278,13 +1278,6 @@ def _check_file_size(self, filepath: str):
  "for large files to avoid loading the file into local memory."
  )
 
- def _create_session_table(self) -> bigquery.TableReference:
- table_name = f"{uuid.uuid4().hex}"
- dataset = bigquery.Dataset(
- bigquery.DatasetReference(self.bqclient.project, "_SESSION")
- )
- return dataset.table(table_name)
-
  def _create_empty_temp_table(
  self,
  schema: Iterable[bigquery.SchemaField],
@@ -1319,7 +1312,7 @@ def _create_sequential_ordering(
  ibis.row_number().cast(ibis_dtypes.int64).name(default_ordering_name)
  )
  table = table.mutate(**{default_ordering_name: default_ordering_col})
- table_ref = self._ibis_to_session_table(
+ table_ref = self._ibis_to_temp_table(
  table,
  cluster_cols=list(index_cols) + [default_ordering_name],
  api_name=api_name,
@@ -1335,7 +1328,7 @@ def _create_sequential_ordering(
  )
  return table, ordering
 
- def _ibis_to_session_table(
+ def _ibis_to_temp_table(
  self,
  table: ibis_types.Table,
  cluster_cols: Iterable[str],